i agree with 1nickt that Text::CSV_XS could be easier, but you say, "this isnt a csv file, it has TABS. well Text::CSV_XS isnt about csv files as much as delimted files, and will take a tab delimiter just as easily.

to show you how easy it is to use Text::CSV_XS i rewrote your code using it. I fixed a few things, ya get yelled at here if you dont use 3 arg opens or lexical limited filehandles ($file1,$file2). i fixed the funny next if 1..$N==$.; to just plain next if ($.==1); and like 1nickt i assumed you meant $prog in the second loop rather than $ID. Another thing i did was follow your code rather than your specs, "and print columns 3 and 5 of whole_pedigree" but your code uses columns 4 and 6 instead. 

#!/usr/bin/perl
use warnings;
use strict;
use diagnostics;

my $hash1;
my $hash2; 


use Text::CSV_XS;

my $sep="\t"; 
my $csv = Text::CSV_XS->new ({ sep_char => $sep });

open (my $file1, "<","wholepedigree_F.txt") or die "Couldn't open whol
+epedigree_F.txt \n";
while (my $row = $csv->getline ($file1)) {
     next if ($.==1);
     my ($ID, $sire, $dam, $F, $FB, $AHC, $FA) = @$row; 
     if ($ID){
        $hash1 -> {$ID} -> {info1} = "$F\t$AHC"; 
        }
     }
close $file1;

my $Output=\*STDOUT; 
open (my $file2, "<","damF.txt") or die "Couldn't open damF.txt\n";
while (my $row = $csv->getline ($file2)) {
     next if ($.==1);
     my ($damID, $damF, $damAHC, $prog) = @$row; 
    if ($prog){
       $hash2 -> {$prog} -> {info2} = "$damID\t$damF\t$damAHC"; 
       }
    if ($prog && ($hash1->{$prog})) {
       my $info1 = $hash1 -> {$prog} -> {info1};
       my $info2 = $hash2 -> {$prog} -> {info2};
       print "$prog\t$info1\t$info2\n";
       }
     }
close $file2;
print "Done";

[download]
There are many parts of 1nickt's code that made sense, like skipping $hash2 and the whole {info1} subtree, but i felt if you saw Text::CSV_XS used in a way more like your original code you may appreciate it more. It came with Activestate perl, so i suspect it is in core and doesnt need to be installed either.

I also didnt use the Text::CSV_XS output routines, so you could comare to your program easier.

In reply to Re: Trouble iterating through a hash by huck
in thread Trouble iterating through a hash by e9292

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.